R&B star Brandy paid homage to her late friend and mentor Whitney Houston on what would've been the legendary singer's 54th birthday, but things took a bad turn.

"Lord have mercy on my soul!!! Happy Born Day Whitney. You live on in me," Brandy wrote on Instagram, captioning a photo collage dedicated to her memories with Whitney. "I can feel your Spirit inside of me and all around me. My angel, my friend, my fairy God Mother. I love you forever... thank you for trusting me with the torch!!! I remember every moment with you and I and I will cherish these miraculous moments forever and ever! I love you.... 8/9-2/11 #WhitneyHouston."

But Monica fans apparently came for Brandy's neck after her post. Brandy and Monica have had bad blood over their respective friendships with Whitney and Brandy fired back at her rival's hive after they made derogatory comments on her IG post.

"Monica needs to really check her evil ass fans," Brandy wrote. "It's so much stuff I can post about the hateful things they say to me... but I will never have time for that. Always thinking something is about her. It's not!!!! It's Never until it was and I was very clear when it was but I did it within my job meaning with my vocals!!! Shit is old. Me and Whitney have nothing to do with anyone but the two of us..."

Things got tense between the two last year after Monica enjoyed a resurgence via the #SoGone Challenge, a viral sensation that shot her 2001 hit "So Gone" back onto the charts. Brandy's performance at the 2016 Soul Train Awards led to rumors that the veteran singer changed her lyrics into a barb aimed at Monica. While performing “Talk About Our Love” she sang that someone is talking on Instagram and letting her “fan base jump in.” Fans on IG believed the singer was referring to her recent tiff with Monica on the ‘Gram over her response to the #SoGoneChallenge.

At the time, Monica quickly shut it all down.

“It’s disappointing to leave ICU and come to my page to see the foolishness of the 90s ever so present amongst BOTH groups,” she writes. “I will forever respect the legend she is & the history we created. All of you guys do the same?? She’s a vocal beast and we’re both great in our own right!!?? This is her moment. She earned and deserves it. No mention or @ of my name needed!!”

But it looks like Brandy is still mad. Was she pressed because Monica posted about Whitney first? Is Brandy that petty? You can check out Monica's IG tribute to Whitney and the screenshots below from Brandy's tirade today (August 9).